I'm pretty mindful to the amount of water used here in the house because we're on our own well so I do set the water level dial to correspond with the load and I don't think I've ever used the 2nd rinse but once to see if it worked years ago. My partner on the other hand is a different story. I don't think in 2 decades he's ever figured out or given a fig that our machine has various wash settings, agitation speeds or water levels. I've basically given up, it's what destroyed my first portable compact him jamming in as much as could be stuffed in there. Same with the dryer, no matter what the load I just set it to the auto dry indicator and it works perfectly regardless of load size, not him, crank it as far as possible to the "more dry".
I never use a warm rinse..I've harped against him for doing it..because I don't see what difference it makes except on the gas bill.